1. Field of the Invention
The present invention relates to a solid electrolytic capacitor.
2. Description of the Related Art
As a conventional solid electrolytic capacitor, Japanese Patent Laying-Open No. 2009-10238 is mentioned, for example. FIG. 2 is a schematic sectional view showing a structure of the solid electrolytic capacitor disclosed in Japanese Patent Laying-Open No. 2009-10238. With reference to FIG. 2, the solid electrolytic capacitor of Japanese Patent Laying-Open No. 2009-10238 includes an anode element 1, a dielectric layer 2 formed at the surface of anode element 1, a conductive polymer layer 3 formed on dielectric layer 2, and a cathode layer 4 formed on conductive polymer layer 3. Cathode layer 4 has a carbon layer 4a made of a layer formed on conductive polymer layer 3 and containing carbon particles, and a silver paste layer 4b made of a layer formed on carbon layer 4a and containing silver particles.
The solid electrolytic capacitor disclosed in Japanese Patent Laying-Open No. 2009-10238 has carbon layer 4a. When forming carbon layer 4a, it is difficult to control the thickness of the carbon layer. If carbon layer 4a is formed thick, cracks will be likely to occur at the time of exterior covering. This raises a problem in that the solid electrolytic capacitor deteriorates in characteristics.
Another possible technique is to form silver paste layer 4b so as to contact conductive polymer layer 3 without forming carbon layer 4a. In this case, however, a gap is left between conductive polymer layer 3 and silver paste layer 4b. This raises a problem in that the solid electrolytic capacitor deteriorates in characteristics.